The first presentation has an absurd amount of new information here on the Merlin 2, plans for a 6m core "Falcon X" with 38mt to LEO, "Falcon X Heavy" with 125mt to LEO, and "Falcon XX" with 140mt to LEO (I shudder to think of what a Falcon XX Heavy would be like):

The second presentation has info on Merlin 2, Raptor (apparently 150klbf thrust) and talks about possibility of modifying Merlin 1 to use LOX/methane for ascent/descent. Also mentions Merlin 2 could be developed and flight qualified in ~3 yrs for ~$1B, ~$50M/engine production, with 1700 klbf vacuum thrust and 322 isp. On the "near-term propulsion needs" slide it also discusses solar-electric tugs and nuclear thermal propsulsion for a Mars stage (?).

Would the Falcon X's 6m core still be transportable by road? What about the Falcon XX's 10m core? Would larger cores be a straightforward scaling of their current processes, or would it involve major changes?

It's also interesting that they're sticking with gas generator cycle for the Merlin 2 instead of staged combustion. Slide 8 of the second presentation discusses some modeling they did which concluded that the advantage of a staged combustion engine (along the lines of the RS-84, which I think they licensed) would have a negligible advantage over gas generator due to higher engine mass.

It's also interesting that they're sticking with gas generator cycle for the Merlin 2 instead of staged combustion.

Not surprised one bit about this. A simpler engine cycle plus it solves the problem of having a separate roll control system when it's used as drop in replacement for F9 first stage (look at the diagram in the 2nd post).

Here's the "near-term propulsion needs" slide, mentioning HLLV propulsion, solar electric propulsion for cargo tugs, nuclear thermal propulsion for Mars stages, and LOX/methane propulsion for ascent/descent. I'd be really curious about what the speaker said along with this slide: Is this merely an outline of what NASA's future needs are, possible things that might be tested at the McGregor Rocket Development Facility, or things that SpaceX is planning on being directly involved in developing?

Would the Falcon X's 6m core still be transportable by road? What about the Falcon XX's 10m core? Would larger cores be a straightforward scaling of their current processes, or would it involve major changes?

7.7 meter diameter, 37.7 meters long. So it could carry a Falcon 9 1st stage, or a Falcon X 2nd stage. Notice the seams in the 1st stage of the Falcon X and XX? Likely means they would be shipped in 2 parts.

The whole system looks like the Atlas V evolution, which isn't a surprise. Either SpaceX copied blindly, or they ended up at the same conclusion because it is the right one...

And just the fact that their propulsion engineer brought up NERVA (which is usually left out even though it is viable) means they have their eyes on the right ball.

The greatest sin of the budget debate will be choosing a no-competition rocket. Crushing the ambition and capabilities of such unique companies (like ULA and SpaceX) will be a real sin. But the demand for "job creation" is stronger than just about anything else.

Would the Falcon X's 6m core still be transportable by road? What about the Falcon XX's 10m core? Would larger cores be a straightforward scaling of their current processes, or would it involve major changes?

7.7 meter diameter, 37.7 meters long. So it could carry a Falcon 9 1st stage, or a Falcon X 2nd stage. Notice the seams in the 1st stage of the Falcon X and XX? Likely means they would be shipped in 2 parts.

There's also barging it from Hawthorne to the Cape through the Panama Canal.

Also, anyone see how they're planning on Raptor having a 470s vacuum Isp? That's a *very* tall claim, which I'm likely to call Incorrect on unless they've got some very good numbers or hotfire tests to back it up. SSME is 453s vacuum, by comparison.

Dreamlifter is less than 6 meter across ID. To my knowledge only Airbus Beluga lifters and the Antonov_An-225 would be capable of carrying a 6 meter stage.

That does not add up, as then it cannot do it's job in transporting the 6m wide 787 components. (787 Fuselage is 5.97m across) The Fuselage of the Dreamlifter is 8.3m wide, and the walls do not look to be over a meter thick....

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chuck - Toilet paper has no real value? Try living with 5 other adults for 6 months in a can with no toilet paper. Man oh man. Toilet paper would be worth it's weight in gold!

Dreamlifter is less than 6 meter across ID. To my knowledge only Airbus Beluga lifters and the Antonov_An-225 would be capable of carrying a 6 meter stage.

That does not add up, as then it cannot do it's job in transporting the 6m wide 787 components. (787 Fuselage is 5.97m across) The Fuselage of the Dreamlifter is 8.3m wide, and the walls do not look to be over a meter thick....

Deleted my incorrect post. Your right, I was referring a bum source. Sorry 787 fuselages are 6.5 meters, so the 6 meter stages would not be a likely issue.

It's kind of expensive to be transporting it via airplane. I'm guessing they'd use a ship.

But really, Super-Heavylift, $1 billion engine development program, Nuclear-thermal rockets... this seems a little incredulous to me... It's all technically possible, but a little outlandish. At least SpaceX has not stopped dreaming (which may be another problem, of course). Good luck! You'll need it.

I do like that they're looking at the solar-electric tug, though... That's one of my favorite hobby-horses!

There's also barging it from Hawthorne to the Cape through the Panama Canal.

Also, anyone see how they're planning on Raptor having a 470s vacuum Isp? That's a *very* tall claim, which I'm likely to call Incorrect on unless they've got some very good numbers or hotfire tests to back it up. SSME is 453s vacuum, by comparison.

I agree that 470s is a tall claim, but remember that the SSME is a ground-lit engine, which generally means the vacuum Isp is less than an equivalent air- or vacuum-lit engine. It still gets good vacuum Isp only because its chamber pressure is so high. If you put a big bell on the SSME, you'd get somewhat better Isp than 453s (perhaps around 470s), but it wouldn't work at sea level anymore. There have been all sorts of engine development projects which shot for ~470s Isp or higher with hydrolox, but none have been very fruitful, perhaps because it just wasn't worth the extra cost/effort rather than just running at, say, 460s Isp.

« Last Edit: 07/31/2010 03:44 AM by Robotbeat »

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Chris Whoever loves correction loves knowledge, but he who hates reproof is stupid.

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